Garden Talk: September 23, 2010

From NGA Editors

Keeping Cut Flowers Fresh

One of the joys of having a flower garden outdoors is being able to bring some of that beauty indoors. Whether you have a cutting garden from which you can harvest armloads of fresh flowers or just a few plants for picking a nosegay or two, the longer the cut flowers stay fresh in the vase, the longer the enjoyment of them.

There is no shortage of suggestions for ways to keep cut flowers fresh, including adding aspirin, bleach, vinegar and sugar to the water in the vase. Some of these recommendations hold up to scientific scrutiny, others turn out to be "horticultural myth." For example, 2 tablespoons of lemon juice, 1 tablespoon of sugar and 1/4 teaspoon of bleach in a quart of warm water will help prolong the life of cut flowers, according to University of California Extension specialists, while aspirin and vinegar are rarely effective.

Now some new research suggests that disinfecting your pruners or scissors before and between making cuts to the stems of flowers may keep them fresh longer. The research, which was presented in The Cut Flower Quarterly, Summer 2010 issue, as reported in the July-August issue of Hortideas, was done on gerbera daisies. When the pruners used to cut the stems were disinfected with a 10% bleach solution before using and between cuts, vase life was extended by as much as three days compared to those cut with pruners that were not disinfected. It was also suggested that disinfecting vases before using might keep cut flowers fresher longer.

Frogs and Fungicides

As scientists note a worldwide decline in amphibians, they have come to consider that these animals are perhaps our environment's "canary in the coal mine," giving us early warning of environmental dangers. While no one is certain yet what is causing the decline, and multiple factors are undoubtedly involved, exposure to pesticides and herbicides is thought to play a role.

Some recent research has established the danger of a commonly used fungicide, chlorothalonil, to tadpoles. This fungicide is not only one of the most commonly used on agricultural crops, it is one that home gardeners use as well. As reported in the September 11, 2010 issue of Science News, researcher Taegan McMahon of the University of South Florida found that when the tadpoles of southern leopard and green tree frogs were exposed to low levels of chlorothalonil (levels a computer model predicted a waterway near a sprayed field will pick up from runoff, or one ten-thousandth of the exposure expected right after a field is treated), all them died within 24 hours. And when tadpoles were exposed for a month to even lower levels of the fungicide (0.0164 micrograms), they died in greater numbers than those is clean water.

Studies by another researcher, Tyrone Hayes of the University of California, Berkeley, as reported in the March 27, 2010 Science News, suggested that the herbicide atrazine, widely used in the production of corn, cotton and turf, may contribute to the decline of frogs in other ways, by feminizing male frogs and interfering with the ability of tadpoles to go through metamorphosis.

Research such as this emphasizes the importance of minimizing the use of pesticides and herbicides in our own gardens and yards, and the importance of supporting farmers who produce crops without these chemicals, by choosing to buy organically produced foods and products whenever possible.

For more information on the environmental threats facing frogs, go to: Science News.

Golden "Fire"

Zinnias have long been garden favorites for their bright blossoms and easy culture. But many have one big drawback- susceptibility to fungal diseases. Now gardeners who want a dose of hot color and improved disease resistance need look no further than the 2011 Fleuroselect Gold Medal winner, Zinnia marylandica Double Zahara ™ Fire.

Developed at the University of Maryland in the early 1980s, Zinnia marylandica is a modern hybrid between Zinnia angustifolia and Zinnia violacea. The cultivar 'Double Zahara ™ Fire' was chosen by Fleuroselect, the International Organisation for the Ornamental Plant Industry, as the first truly double zinnia with a high degree of disease tolerance. This compact selection grows about 14 inches tall and wide and is covered all summer long with brilliant red-orange blossoms. Its prolific flowering and lack of disease problems lead to superior landscape performance, making it great for mass plantings. Look for it at garden centers and greenhouses next spring.

All the Dirt on Tomatoes

Tomato season is coming to a close for gardeners in many parts of the country. But until frost hits, it's time to harvest and enjoy fresh tomatoes, and perhaps preserve some of the bounty for winter eating. If you want to find out how to can, freeze and dry tomatoes, along with advice on preparing fresh tomatoes for use in recipes, you'll enjoy the Web site Tomato Dirt. It includes information on both water bath and pressure canning and step-by-step advice on freezing whole, chopped, sliced and pureed tomatoes.

Besides all this helpful information on using and saving your harvest, the site has lots of information to put to good use next growing season, with advice on starting tomatoes from seed, planting, staking, watering, fertilizing and dealing with tomato problems. There are sections on growing tomatoes in pots and hanging containers and saving seeds, even fun tomato facts and trivia. Did you know that the heaviest tomato on record weighed 7 pounds 12 ounces and the gardener who grew it sliced it up to make sandwiches for 21 family members?

And just in time for Halloween, there's even a section with instructions for making your own tomato costume! For those not inclined to sew-it-yourself, there are links to sites selling ready-made tomato costumes. Don't let the Giant Pumpkin hog the spotlight; trick-or-treat as the Giant Tomato!